﻿/*
** uliolib.c, copyright 2010-2012, Shmuel Zeigerman.
** A modification of Standard I/O (and system) library
** giving it capability of working with Unicode paths.
** Same license as Lua 5.1.
**
** This modification contains an implementation for Windows only.
*/

/*
** $Id: liolib.c,v 2.73.1.3 2008/01/18 17:47:43 roberto Exp $
** Standard I/O (and system) library
** See Copyright Notice in lua.h
*/


#include <errno.h>
#include <stdio.h>
#include <stdlib.h>
#include <string.h>

#define liolib_c
#define LUA_LIB

#include "lua.h"

#include "lauxlib.h"
#include "lualib.h"

#include "lf_string.h"

#undef lua_popen
#define lua_popen(L,c,m)	((void)L, _wpopen(c,m))


#define IO_INPUT	1
#define IO_OUTPUT	2


static const char *const fnames[] = {"input", "output"};


static int pushresult(lua_State *L, int stat, const wchar_t *filename)
{
	int en = errno;  /* calls to Lua API may change this value */

	if (stat)
	{
		lua_pushboolean(L, 1);
		return 1;
	}
	else
	{
		lua_pushnil(L);

		if (filename)
		{
			const char *utf8name = push_utf8_string(L, filename, -1);
			lua_pushfstring(L, "%s: %s", utf8name, strerror(en));
			lua_remove(L, -2);
		}
		else
			lua_pushfstring(L, "%s", strerror(en));

		lua_pushinteger(L, en);
		return 3;
	}
}


static void fileerror(lua_State *L, int arg, const wchar_t *filename)
{
	const char* utf8name = push_utf8_string(L, filename, -1);
	lua_pushfstring(L, "%s: %s", utf8name, strerror(errno));
	luaL_argerror(L, arg, lua_tostring(L, -1));
}


#define tofilep(L)	((FILE **)luaL_checkudata(L, 1, LUA_FILEHANDLE))


static int io_type(lua_State *L)
{
	void *ud;
	luaL_checkany(L, 1);
	ud = lua_touserdata(L, 1);
	lua_getfield(L, LUA_REGISTRYINDEX, LUA_FILEHANDLE);

	if (ud == NULL || !lua_getmetatable(L, 1) || !lua_rawequal(L, -2, -1))
		lua_pushnil(L);  /* not a file */
	else if (*((FILE **)ud) == NULL)
		lua_pushliteral(L, "closed file");
	else
		lua_pushliteral(L, "file");

	return 1;
}


static FILE *tofile(lua_State *L)
{
	FILE **f = tofilep(L);

	if (*f == NULL)
		luaL_error(L, "attempt to use a closed file");

	return *f;
}



/*
** When creating file handles, always creates a `closed' file handle
** before opening the actual file; so, if there is a memory error, the
** file is not left opened.
*/
static FILE **newfile(lua_State *L)
{
	FILE **pf = (FILE **)lua_newuserdata(L, sizeof(FILE *));
	*pf = NULL;  /* file handle is currently `closed' */
	luaL_getmetatable(L, LUA_FILEHANDLE);
	lua_setmetatable(L, -2);
	return pf;
}


/*
** function to (not) close the standard files stdin, stdout, and stderr
*/
static int io_noclose(lua_State *L)
{
	lua_pushnil(L);
	lua_pushliteral(L, "cannot close standard file");
	return 2;
}


/*
** function to close 'popen' files
*/
static int io_pclose(lua_State *L)
{
	FILE **p = tofilep(L);
	int ok = lua_pclose(L, *p);
	*p = NULL;
	return pushresult(L, ok, NULL);
}


/*
** function to close regular files
*/
static int io_fclose(lua_State *L)
{
	FILE **p = tofilep(L);
	int ok = (fclose(*p) == 0);
	*p = NULL;
	return pushresult(L, ok, NULL);
}


static int aux_close(lua_State *L)
{
	lua_getfenv(L, 1);
	lua_getfield(L, -1, "__close");
	return (lua_tocfunction(L, -1))(L);
}


static int io_close(lua_State *L)
{
	if (lua_isnone(L, 1))
		lua_rawgeti(L, LUA_ENVIRONINDEX, IO_OUTPUT);

	tofile(L);  /* make sure argument is a file */
	return aux_close(L);
}


static int io_gc(lua_State *L)
{
	FILE *f = *tofilep(L);

	/* ignore closed files */
	if (f != NULL)
		aux_close(L);

	return 0;
}


static int io_tostring(lua_State *L)
{
	FILE *f = *tofilep(L);

	if (f == NULL)
		lua_pushliteral(L, "file (closed)");
	else
		lua_pushfstring(L, "file (%p)", f);

	return 1;
}


static int io_open(lua_State *L)
{
	const wchar_t *filename = check_utf8_string(L, 1, NULL);
	const wchar_t *mode = opt_utf8_string(L, 2, L"r");
	FILE **pf = newfile(L);
	int i = 0;

	/* check whether 'mode' matches '[rwa]%+?b?' */
	if (!(mode[i] != L'\0' && wcschr(L"rwa", mode[i++]) != NULL &&
	        (mode[i] != L'+' || ++i) &&  /* skip if char is '+' */
	        (mode[i] != L'b' || ++i) &&  /* skip if char is 'b' */
	        (mode[i] == L'\0')))
	{
		push_utf8_string(L, mode, -1);
		return luaL_error(L, "invalid mode " LUA_QS
		                  " (should match " LUA_QL("[rwa]%%+?b?") ")", lua_tostring(L, -1));
	}

	*pf = _wfopen(filename, mode);
	return (*pf == NULL) ? pushresult(L, 0, filename) : 1;
}


/*
** this function has a separated environment, which defines the
** correct __close for 'popen' files
*/
static int io_popen(lua_State *L)
{
	const wchar_t *filename = check_utf8_string(L, 1, NULL);
	const wchar_t *mode = opt_utf8_string(L, 2, L"r");
	FILE **pf = newfile(L);
	*pf = lua_popen(L, filename, mode);
	return (*pf == NULL) ? pushresult(L, 0, filename) : 1;
}


static int io_tmpfile(lua_State *L)
{
	FILE **pf = newfile(L);
	*pf = tmpfile();
	return (*pf == NULL) ? pushresult(L, 0, NULL) : 1;
}


static FILE *getiofile(lua_State *L, int findex)
{
	FILE *f;
	lua_rawgeti(L, LUA_ENVIRONINDEX, findex);
	f = *(FILE **)lua_touserdata(L, -1);

	if (f == NULL)
		luaL_error(L, "standard %s file is closed", fnames[findex - 1]);

	return f;
}


static int g_iofile(lua_State *L, int f, const wchar_t *mode)
{
	if (!lua_isnoneornil(L, 1))
	{
		const wchar_t *filename = lua_tostring(L, 1) ?
		                          check_utf8_string(L, 1, NULL) : NULL;

		if (filename)
		{
			FILE **pf = newfile(L);
			*pf = _wfopen(filename, mode);

			if (*pf == NULL)
				fileerror(L, 1, filename);
		}
		else
		{
			tofile(L);  /* check that it's a valid file handle */
			lua_pushvalue(L, 1);
		}

		lua_rawseti(L, LUA_ENVIRONINDEX, f);
	}

	/* return current value */
	lua_rawgeti(L, LUA_ENVIRONINDEX, f);
	return 1;
}


static int io_input(lua_State *L)
{
	return g_iofile(L, IO_INPUT, L"r");
}


static int io_output(lua_State *L)
{
	return g_iofile(L, IO_OUTPUT, L"w");
}


static int io_readline(lua_State *L);


static void aux_lines(lua_State *L, int idx, int toclose)
{
	lua_pushvalue(L, idx);
	lua_pushboolean(L, toclose);  /* close/not close file when finished */
	lua_pushcclosure(L, io_readline, 2);
}


static int f_lines(lua_State *L)
{
	tofile(L);  /* check that it's a valid file handle */
	aux_lines(L, 1, 0);
	return 1;
}


static int io_lines(lua_State *L)
{
	if (lua_isnoneornil(L, 1))     /* no arguments? */
	{
		/* will iterate over default input */
		lua_rawgeti(L, LUA_ENVIRONINDEX, IO_INPUT);
		return f_lines(L);
	}
	else
	{
		const wchar_t *filename = check_utf8_string(L, 1, NULL);
		FILE **pf = newfile(L);
		*pf = _wfopen(filename, L"r");

		if (*pf == NULL)
			fileerror(L, 1, filename);

		aux_lines(L, lua_gettop(L), 1);
		return 1;
	}
}


/*
** {======================================================
** READ
** =======================================================
*/


static int read_number(lua_State *L, FILE *f)
{
	lua_Number d;

	if (fscanf(f, LUA_NUMBER_SCAN, &d) == 1)
	{
		lua_pushnumber(L, d);
		return 1;
	}
	else return 0;  /* read fails */
}


static int test_eof(lua_State *L, FILE *f)
{
	int c = getc(f);
	ungetc(c, f);
	lua_pushlstring(L, NULL, 0);
	return (c != EOF);
}


static int read_line(lua_State *L, FILE *f)
{
	luaL_Buffer b;
	luaL_buffinit(L, &b);

	for(;;)
	{
		size_t l;
		char *p = luaL_prepbuffer(&b);

		if (fgets(p, LUAL_BUFFERSIZE, f) == NULL)     /* eof? */
		{
			luaL_pushresult(&b);  /* close buffer */
			return (lua_objlen(L, -1) > 0);  /* check whether read something */
		}

		l = strlen(p);

		if (l == 0 || p[l-1] != '\n')
			luaL_addsize(&b, l);
		else
		{
			luaL_addsize(&b, l - 1);  /* do not include `eol' */
			luaL_pushresult(&b);  /* close buffer */
			return 1;  /* read at least an `eol' */
		}
	}
}


static int read_line_bin (lua_State *L, FILE *f) {
	luaL_Buffer b;
	luaL_buffinit(L, &b);
	for (;;) {
		char *q, *p = luaL_prepbuffer(&b);
		memset(p, '\n', LUAL_BUFFERSIZE);
		if (fgets(p, LUAL_BUFFERSIZE, f) == NULL) {  /* eof? */
			luaL_pushresult(&b);  /* close buffer */
			return (lua_objlen(L, -1) > 0);  /* check whether read something */
		}
		for (q=p+LUAL_BUFFERSIZE-1; q>p && *q; --q) { /* find last '\0' char */
		}
		if (q-- > p) {
			if (*q == '\n') {
				luaL_addsize(&b, q-p);
				luaL_pushresult(&b);  /* close buffer */
				return 1;
			}
			luaL_addsize(&b, q-p+1);
		}
	}
}


static int read_chars(lua_State *L, FILE *f, size_t n)
{
	size_t rlen;  /* how much to read */
	size_t nr;  /* number of chars actually read */
	luaL_Buffer b;
	luaL_buffinit(L, &b);
	rlen = LUAL_BUFFERSIZE;  /* try to read that much each time */

	do
	{
		char *p = luaL_prepbuffer(&b);

		if (rlen > n) rlen = n;   /* cannot read more than asked */

		nr = fread(p, sizeof(char), rlen, f);
		luaL_addsize(&b, nr);
		n -= nr;  /* still have to read `n' chars */
	}
	while(n > 0 && nr == rlen);     /* until end of count or eof */

	luaL_pushresult(&b);  /* close buffer */
	return (n == 0 || lua_objlen(L, -1) > 0);
}


static int g_read(lua_State *L, FILE *f, int first)
{
	int nargs = lua_gettop(L) - 1;
	int success;
	int n;
	clearerr(f);

	if (nargs == 0)     /* no arguments? */
	{
		success = read_line(L, f);
		n = first+1;  /* to return 1 result */
	}
	else    /* ensure stack space for all results and for auxlib's buffer */
	{
		luaL_checkstack(L, nargs+LUA_MINSTACK, "too many arguments");
		success = 1;

		for(n = first; nargs-- && success; n++)
		{
			if (lua_type(L, n) == LUA_TNUMBER)
			{
				size_t l = (size_t)lua_tointeger(L, n);
				success = (l == 0) ? test_eof(L, f) : read_chars(L, f, l);
			}
			else
			{
				const char *p = lua_tostring(L, n);
				luaL_argcheck(L, p && p[0] == '*', n, "invalid option");

				switch(p[1])
				{
					case 'n':  /* number */
						success = read_number(L, f);
						break;
					case 'l':  /* line */
						success = read_line(L, f);
						break;
					case 'b':  /* "binary" line (LuaFAR extension) */
						success = read_line_bin(L, f);
						break;
					case 'a':  /* file */
						read_chars(L, f, ~((size_t)0));  /* read MAX_SIZE_T chars */
						success = 1; /* always success */
						break;
					default:
						return luaL_argerror(L, n, "invalid format");
				}
			}
		}
	}

	if (ferror(f))
		return pushresult(L, 0, NULL);

	if (!success)
	{
		lua_pop(L, 1);  /* remove last result */
		lua_pushnil(L);  /* push nil instead */
	}

	return n - first;
}


static int io_read(lua_State *L)
{
	return g_read(L, getiofile(L, IO_INPUT), 1);
}


static int f_read(lua_State *L)
{
	return g_read(L, tofile(L), 2);
}


static int io_readline(lua_State *L)
{
	FILE *f = *(FILE **)lua_touserdata(L, lua_upvalueindex(1));
	int sucess;

	if (f == NULL)   /* file is already closed? */
		luaL_error(L, "file is already closed");

	sucess = read_line(L, f);

	if (ferror(f))
		return luaL_error(L, "%s", strerror(errno));

	if (sucess) return 1;
	else    /* EOF */
	{
		if (lua_toboolean(L, lua_upvalueindex(2)))     /* generator created file? */
		{
			lua_settop(L, 0);
			lua_pushvalue(L, lua_upvalueindex(1));
			aux_close(L);  /* close it */
		}

		return 0;
	}
}

/* }====================================================== */


static int g_write(lua_State *L, FILE *f, int arg)
{
	int nargs = lua_gettop(L) - 1;
	int status = 1;

	for(; nargs--; arg++)
	{
		if (lua_type(L, arg) == LUA_TNUMBER)
		{
			/* optimization: could be done exactly as for strings */
			status = status &&
			         fprintf(f, LUA_NUMBER_FMT, lua_tonumber(L, arg)) > 0;
		}
		else
		{
			size_t l;
			const char *s = luaL_checklstring(L, arg, &l);
			status = status && (fwrite(s, sizeof(char), l, f) == l);
		}
	}

	return pushresult(L, status, NULL);
}


static int io_write(lua_State *L)
{
	return g_write(L, getiofile(L, IO_OUTPUT), 1);
}


static int f_write(lua_State *L)
{
	return g_write(L, tofile(L), 2);
}

/* _fseeki64 and _ftelli64 work incorrectly when compiled with MinGW hence the following: */
#if defined(__MINGW32__)
	#define FSEEK fseeko64
	#define FTELL ftello64
#else
	#define FSEEK _fseeki64
	#define FTELL _ftelli64
#endif

static int f_seek(lua_State *L)
{
	static const int mode[] = {SEEK_SET, SEEK_CUR, SEEK_END};
	static const char *const modenames[] = {"set", "cur", "end", NULL};
	FILE *f = tofile(L);
	int op = luaL_checkoption(L, 2, "cur", modenames);
	lua_Number p3 = luaL_optnumber(L, 3, 0);
	__int64 offset = (__int64)p3;
	luaL_argcheck(L, (lua_Number)offset == p3, 3,
	              "not an integer in proper range");
	op = FSEEK(f, offset, mode[op]);

	if (op)
		return pushresult(L, 0, NULL);  /* error */
	else
	{
		lua_pushnumber(L, (lua_Number)FTELL(f));
		return 1;
	}
}


static int f_setvbuf(lua_State *L)
{
	static const int mode[] = {_IONBF, _IOFBF, _IOLBF};
	static const char *const modenames[] = {"no", "full", "line", NULL};
	FILE *f = tofile(L);
	int op = luaL_checkoption(L, 2, NULL, modenames);
	lua_Integer sz = luaL_optinteger(L, 3, LUAL_BUFFERSIZE);
	int res = setvbuf(f, NULL, mode[op], sz);
	return pushresult(L, res == 0, NULL);
}



static int io_flush(lua_State *L)
{
	return pushresult(L, fflush(getiofile(L, IO_OUTPUT)) == 0, NULL);
}


static int f_flush(lua_State *L)
{
	return pushresult(L, fflush(tofile(L)) == 0, NULL);
}


static int f_rawhandle(lua_State *L)
{
#ifdef __GNUC__
	lua_pushlightuserdata(L, tofile(L));
	return 1;
#else
	return luaL_error(L, "rawhandle is only available in GCC compilations.");
#endif
}


static const luaL_Reg iolib[] =
{
	{"close", io_close},
	{"flush", io_flush},
	{"input", io_input},
	{"lines", io_lines},
	{"open", io_open},
	{"output", io_output},
	{"popen", io_popen},
	{"read", io_read},
	{"tmpfile", io_tmpfile},
	{"type", io_type},
	{"write", io_write},
	{NULL, NULL}
};


static const luaL_Reg flib[] =
{
	{"close", io_close},
	{"flush", f_flush},
	{"lines", f_lines},
	{"read", f_read},
	{"seek", f_seek},
	{"setvbuf", f_setvbuf},
	{"write", f_write},
	{"rawhandle", f_rawhandle},
	{"__gc", io_gc},
	{"__tostring", io_tostring},
	{NULL, NULL}
};


static void createmeta(lua_State *L)
{
	luaL_newmetatable(L, LUA_FILEHANDLE);  /* create metatable for file handles */
	lua_pushvalue(L, -1);  /* push metatable */
	lua_setfield(L, -2, "__index");  /* metatable.__index = metatable */
	luaL_register(L, NULL, flib);  /* file methods */
}


static void createstdfile(lua_State *L, FILE *f, int k, const char *fname)
{
	*newfile(L) = f;

	if (k > 0)
	{
		lua_pushvalue(L, -1);
		lua_rawseti(L, LUA_ENVIRONINDEX, k);
	}

	lua_pushvalue(L, -2);  /* copy environment */
	lua_setfenv(L, -2);  /* set it */
	lua_setfield(L, -3, fname);
}


static void newfenv(lua_State *L, lua_CFunction cls)
{
	lua_createtable(L, 0, 1);
	lua_pushcfunction(L, cls);
	lua_setfield(L, -2, "__close");
}


LUALIB_API int luaopen_uio(lua_State *L)
{
	createmeta(L);
	/* create (private) environment (with fields IO_INPUT, IO_OUTPUT, __close) */
	newfenv(L, io_fclose);
	lua_replace(L, LUA_ENVIRONINDEX);
	/* open library */
	luaL_register(L, LUA_IOLIBNAME, iolib);
	/* create (and set) default files */
	newfenv(L, io_noclose);  /* close function for default files */
	createstdfile(L, stdin, IO_INPUT, "stdin");
	createstdfile(L, stdout, IO_OUTPUT, "stdout");
	createstdfile(L, stderr, 0, "stderr");
	lua_pop(L, 1);  /* pop environment for default files */
	lua_getfield(L, -1, "popen");
	newfenv(L, io_pclose);  /* create environment for 'popen' */
	lua_setfenv(L, -2);  /* set fenv for 'popen' */
	lua_pop(L, 1);  /* pop 'popen' */
	return 1;
}

